Rut gon : A = x|x - 2| / x^2 + 8x - 20 .
Những câu hỏi liên quan
Rut gon A=\(\frac{x\left(x-2\right)}{x^2+8x-20}\)
rut gon (x^2+2x+1)\(x-1)^2:(2x^2+4x+2)\(4x^2-8x+4)
\(=\frac{\left(x+1\right)^2}{\left(x-1\right)^2}:\frac{2\left(x+1\right)^2}{4\left(x-1\right)^2}=\frac{\left(x+1\right)^2}{\left(x-1\right)^2}.\frac{4\left(x-1\right)^2}{2\left(x+1\right)^2}=2\)
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Rut gon bt
\(A=[\frac{(x-1)^2}{x^2+x+1}-\frac{1+4x-2x^2}{x^3-1}-\frac{1}{1-x}]^2:\frac{8x^3+1}{8x^2-4x+2}\)
Rut gon bieu thuc:
A=\(8x^{n-1}.\left(\frac{1}{2}x^{n+1}-\frac{3}{4}x\right)\)
phan tich tu va mau thanh nhan tu roi rut gon
a, 3x^2-12x+12/x^4-8x
b,7x^2+14x+7/3x^2+3x
Câu a :
\(\dfrac{3x^2-12x+12}{x^4-8x}\)
\(=\dfrac{3\left(x^2-4x+4\right)}{x\left(x^3-8\right)}\)
\(=\dfrac{3\left(x-2\right)^2}{x\left(x-2\right)\left(x^2+2x+4\right)}\)
\(=\dfrac{3\left(x-2\right)}{x\left(x^2+2x+4\right)}\)
Câu b :
\(\dfrac{7x^2+14x+7}{3x^2+3x}\)
\(=\dfrac{7\left(x+1\right)^2}{3x\left(x+1\right)}=\dfrac{7\left(x+1\right)}{3x}\)
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Rut gon cac bieu thuc sau:
2(x-y).(x+y)+(x-y)^2+(x+y)^2
(2x-3).(4x^2+6x+9) -(54+8x)
(3x+y).(9x^2-3xy+y^2)-(3x-y).(9x^2+3xy+y^2)
(a +b +c)^2-(a-c)^2-2ab+2bc
\(a,\)\(2\left(x-y\right)\left(x+y\right)+\left(x-y\right)^2+\left(x+y\right)^2.\)
\(=\left[\left(x-y\right)+\left(x+y\right)\right]^2=\left(x-y+x+y\right)^2=x^2\)
\(b,\)\(\left(2x-3\right)\left(4x^2+6x+9\right)-\left(54+8x\right)\)
\(=8x^2-27-54-8x=8x^2-8x-81\)
\(c,\)\(\left(3x+y\right)\left(9x^2-3xy+y^2\right)-\left(3x-y\right)\left(9x^2+3xy+y^2\right)\)
\(=27x^3+y^3-\left(27x^3-y^3\right)=2y^3\)
\(d,\)\(\left(a+b+c\right)^2-\left(a-c\right)^2-2ab+2bc\)
\(=a^2+b^2+c^2+2ab+2bc+2ac-a^2+2ac-c^2-2ab+2bc\)
\(=b^2+4bc+4ac\)
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rut gon phan thuc:
1 \(\dfrac{x^2-18x-19}{x^2-1}\)
2 \(\dfrac{x\left(4x^2-8x+4\right)}{2x^3-2x^2}\)
1) \(\dfrac{x^2-18x-19}{x^2-1}=\dfrac{x^2-19x+x-19}{\left(x-1\right)\left(x+1\right)}=\dfrac{x\left(x-19\right)+x-19}{\left(x-1\right)\left(x+1\right)}=\dfrac{\left(x-19\right)\left(x+1\right)}{\left(x-1\right)\left(x+1\right)}=\dfrac{x-19}{x-1}\)
2) \(\dfrac{x\left(4x^2-8x+4\right)}{2x^3-2x^2}=\dfrac{4x\left(x^2-2x+1\right)}{2x^2\left(x-1\right)}=\dfrac{4x\left(x-1\right)^2}{2x^2\left(x-1\right)}=\dfrac{2\left(x-1\right)}{x}\)
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1.=\(\dfrac{(x^2+x)-(19x+19)}{(x+1)(x-1)}\)
=\(\dfrac{x(x+1)-19(x+1)}{(x+1)(x-1)}\)
=\(\dfrac{(x+1)(x-19)}{(x+1)(x-1)}\)
=\(\dfrac{x-19}{x-1}\)
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(x-y)^2-4
x^2-16(x+y)^2
8x^3+36x^2y+5xy^2+27y^3
rut gon
a)(x^2+4)(x^2-4)-(x^2+1)(x^2-1)
b)(y-3)(y+3)(y^2+9)(y^2+2)(y^2-2)
Bài 1
( x - y )2 - 4
= ( x - y )2 - 22
= ( x - y - 2 )( x - y + 2 )
x2 - 16( x + y )2
= x2 - 42( x + y )2
= x2 - ( 4x + 4y )2
= ( x2 - 4x - 4y )( x2 - 4x + 4y )
8x3 + 36x2y + 54xy2 + 27y3
= ( 2x )3 + 3.( 2x )2.3y + 3.2x.( 3y )2 + ( 3y )3
= ( 2x + 3y )3
Bài 2.
a) ( x2 + 4 )( x2 - 4 ) - ( x2 + 1 )( x2 - 1 )
= [ ( x2 )2 - 42 ] - [ ( x2 )2 - 12 ]
= x4 - 16 - x4 + 1
= -15
b) ( y - 3 )( y + 3 )( y2 + 9 )( y2 + 2 )( y2 - 2 )
= [ ( y - 3 )( y + 3 )( y2 + 9 ) ][ ( y2 + 2 )( y2 - 2 ) ]
= { [ ( y - 3 )( y + 3 ) ]( y2 + 9 ) }[ ( y2 )2 - 22 ]
= [ ( y2 - 9 )( y2 + 9 ) ]( y4 - 4 )
= ( y4 - 81 )( y4 - 4 )
= y4( y4 - 4 ) - 81( y4 - 4 )
= y8 - 4y4 - 81y4 + 324
= y8 - 85y4 + 324
Rut gon: \(P=\frac{2.lx-4l}{x^2+x-20}\)